Double patterning is technology for exposing a circuit pattern of which has advanced beyond the resolution of lithography technology by dividing the circuit pattern into two circuit patterns that fall within the range of the resolution of lithography technology.
On the other hand, it is possible to deem patterning technology by a sidewall as one kind of double patterning. Hereinafter, this is sometimes referred to as a “sidewall method”. The patterning technology by a sidewall is a technique for forming a pattern using a sidewall formed on the side face of a mandrel as a mask.
However, the double patterning technology by a sidewall does not permit an H-shaped wiring pattern (stitch pattern), and therefore, the degree of freedom in a design of a wiring layout is low.